The present invention relates generally to timers and more particularly to the art of controlling the pumping of a well such as an oil well or other fluid deep wells.
While the discussion herein of the present and the prior art relates to the pumping of oil wells, it should be borne in mind that the apparatus of the present invention may be utilized to control devices other than well pumps, and further that the apparatus of the present invention may be utilized to control pump motors other than electrical pump motors, such as natural gas pump motors.
With the depletion of natural gas and oil in the American oil fields, it became necessary to use secondary and tertiary methods of production in addition to the natural production of old stripper wells. There are many different methods of secondary and tertiary recovery. For example, the use of water flooding has been effective in some geographical areas, and where water flooding was found not to be effective, the industry has used different agents and additives to produce a drive of the oil to the well that is compatible with the surrounding sand. Air pressure, natural gas pressure and other gases have also been used in different combinations of producing wells and injection wells to obtain production. One of the more recent methods used for secondary recovery is called hydrofracturing, wherein a high pressure is placed on the sand through the use of pumps, this pressure being high enough to fracture or crack the sand, to allow oil to flow more freely into the well.
Almost all oil-bearing sands or strata are unique and may vary from one location to another in permeability, porosity, resistivity, conductivity and rock pressure or gas pressure in the sand. With all these above-outlined variables, a need is established for a well pump control for extracting the oil which is highly flexible in its control capabilities as well as being able, in some cases, to respond to other commands to increase, retard, or stop the rate of flow. In addition, many oil fields utilize a large number of wells, and the present inventor has further discovered in this regard that there is a need for not only local but remote control for monitoring and changing production on each individual well to respond to the recovery method being utilized for optimum performance. In fact, it has been discovered that by varying the pumping cycle of the well, pumping cycles can be increased by as much as 50%, thus bringing about the need for an almost infinitely variable pump controller.
Current controllers on the market which are provided to handle this application are made up of standard electro-mechanical timers with varying means of adjustment. Some are 24 hour timers, some are 24 hour cycle timers with a minute setting of 15 minutes off and 15 minutes on. Others are 7 day timers with skip-a-day option available. Yet others are percentage timers with time on and off expressed in percent of 24 hours. None of these prior art timers are programmable for multi-function capability making it necessary at times to change timers as a well changes its production characteristics. Present timers utilize electro-mechanical motors and coils for timing and switching which are susceptible to moisture and corrosive atmospheric contamination which results in short life for such timer units. Also, transients from lightning are a factor in many failures as well as voltage regulation, phase unbalance and poor frequency regulation. Many oil companies generate their own power, and in some situations this has created a problem in maintaining an acceptable or clean power output without harmonics on the AC power which result in premature failures of the prior art timers. None of the prior art timers can respond to an external output and change its scheduling accordingly. In the event of power failure or shutdown, the prior art pump controllers must be reset to proper time again. Nor do the prior art timers have the ability to communicate to a local or remote location, nor are they capable of being reset or changed from a remote location. In addition, many of the prior art timers must also have their coils and clock motors changed to handle different voltages, which may be experienced throughout a given oil field. In addition, the pump controllers of the prior art are not capable of analyzing the production results and capabilities of a given well.